1 files changed, 4 insertions, 25 deletions

diff --git a/sphinx/domains/math.py b/sphinx/domains/math.py
index 248a7a2a6..88db1ad0e 100644
--- a/sphinx/domains/math.py
+++ b/sphinx/domains/math.py
@@ -8,14 +8,12 @@
     :license: BSD, see LICENSE for details.
 """
 
-import warnings
-from typing import Any, Dict, Iterable, List, Tuple
+from typing import TYPE_CHECKING, Any, Dict, Iterable, List, Tuple
 
 from docutils import nodes
 from docutils.nodes import Element, Node, make_id, system_message
 
 from sphinx.addnodes import pending_xref
-from sphinx.deprecation import RemovedInSphinx40Warning
 from sphinx.domains import Domain
 from sphinx.environment import BuildEnvironment
 from sphinx.locale import __
@@ -23,8 +21,7 @@ from sphinx.roles import XRefRole
 from sphinx.util import logging
 from sphinx.util.nodes import make_refnode
 
-if False:
-    # For type annotation
+if TYPE_CHECKING:
     from sphinx.application import Sphinx
     from sphinx.builders import Builder
 
@@ -44,10 +41,10 @@ class MathDomain(Domain):
     name = 'math'
     label = 'mathematics'
 
-    initial_data = {
+    initial_data: Dict = {
         'objects': {},  # labelid -> (docname, eqno)
         'has_equations': {},  # docname -> bool
-    }  # type: Dict
+    }
     dangling_warnings = {
         'eq': 'equation not found: %(target)s',
     }
@@ -139,24 +136,6 @@ class MathDomain(Domain):
     def get_objects(self) -> List:
         return []
 
-    def add_equation(self, env: BuildEnvironment, docname: str, labelid: str) -> int:
-        warnings.warn('MathDomain.add_equation() is deprecated.',
-                      RemovedInSphinx40Warning, stacklevel=2)
-        if labelid in self.equations:
-            path = env.doc2path(self.equations[labelid][0])
-            msg = __('duplicate label of equation %s, other instance in %s') % (labelid, path)
-            raise UserWarning(msg)
-        else:
-            eqno = self.get_next_equation_number(docname)
-            self.equations[labelid] = (docname, eqno)
-            return eqno
-
-    def get_next_equation_number(self, docname: str) -> int:
-        warnings.warn('MathDomain.get_next_equation_number() is deprecated.',
-                      RemovedInSphinx40Warning, stacklevel=2)
-        targets = [eq for eq in self.equations.values() if eq[0] == docname]
-        return len(targets) + 1
-
     def has_equations(self, docname: str = None) -> bool:
         if docname:
             return self.data['has_equations'].get(docname, False)